Method for coating a substrate for euv lithography and substrate with photoresist layer

Abstract

A method for coating a substrate for EUV lithography includes coating a photoresist layer on the substrate. A device manufacturing method using a lithographic projection apparatus includes providing a substrate that is at least partially covered by a photoresist layer by coating the photoresist layer on the substrate and projecting a patterned beam of radiation onto a target portion of the photoresist layer. A substrate includes a photoresist layer.

1 . A method for coating a substrate for EUV lithography, comprising: 
 coating a photoresist layer on the substrate;    providing an EUV transmissive top coat on the photoresist layer, wherein the EUV transmissive top coat comprises a polymer that includes one or more of the following atoms: beryllium, boron, carbon, silicon, zirconium, niobium and molybdenum.    
     
     
         2 . A method according to  claim 1 , wherein the top coat comprises one or more of the following polymers: polysilanes, polysilylenes, polysiloxanes, silylated polyhydroxystyrene, silane containing polymers, silsesquioxane polymers, acryl silane polymers, methacryl silane polymers and silylated polymers.  
     
     
         3 . A method according to  claim 1 , wherein the top coat has a final thickness such that the transmission of EUV radiation is higher than 50%.  
     
     
         4 . A method according to  claim 1 , wherein the top coat has a transmission for DUV and UV radiation of less than 50%.  
     
     
         5 . A device manufacturing method using a lithographic projection apparatus, comprising: 
 providing a substrate that is at least partially covered by a photoresist layer;    providing an EUV transmissive top coat on the photoresist layer, wherein the EUV transmissive top coat comprises a polymer that includes one or more of the following atoms: beryllium, boron, carbon, silicon, zirconium, niobium and molybdenum; and    projecting a patterned beam of radiation onto a target portion of the photoresist layer.    
     
     
         6 . A method according to  claim 5 , wherein the top coat comprises one or more of the following polymers: polysilanes, polysilylenes, polysiloxanes, silylated polyhydroxystyrene, silane containing polymers, silsesquioxane polymers, acryl silane polymers, methacryl silane polymers and silylated polymers.  
     
     
         7 . A method according to  claim 5 , wherein the top coat has a final thickness such that the transmission of EUV radiation is higher than 50%.  
     
     
         8 . A method according to  claim 5 , wherein the top coat has a transmission for DUV and UV radiation of less than 50%.  
     
     
         9 . A coat for use as top coat on a photoresist layer, wherein the coat comprises a polymer that includes one or more of the following atoms: beryllium, boron, carbon, silicon, zirconium, niobium and molybdenum, and the coat enables at least one of diminishing of outgassing of a contaminant from the photoresist layer and preventing contamination of the photoresist.  
     
     
         10 . A coat according to  claim 9 , wherein the contaminant is a compound selected from water, hydrocarbons and compounds comprising at least one atom selected from the group consisting of F, Si, P, S and Cl.  
     
     
         11 . A coat according to  claim 9 , wherein the coat comprises one or more of the following polymers: polysilanes, polysilylenes, polysiloxanes, silylated polyhydroxystyrene, silane containing polymers, silsesquioxane polymers, acryl silane polymers, methacryl silane polymers and silylated polymers.  
     
     
         12 . A coat according to one of  claim 9 , wherein the coat is EUV transmissive.  
     
     
         13 . A coat according to  claim 12 , wherein the coat has a thickness such that the transmission of EUV radiation is higher than 50%.  
     
     
         14 . A coat according to of  claim 12 , wherein the coat has a transmission for DUV and UV radiation of less than 50%.  
     
     
         15 . A substrate comprising a photoresist layer and an EUV transmissive top coat on the photoresist layer, wherein the EUV transmissive top coat comprises a polymer that includes one or more of the following atoms: beryllium, boron, carbon, silicon, zirconium, niobium and molybdenum.  
     
     
         16 . A substrate according to  claim 15 , wherein the photoresist layer comprises an EUV photoresist.  
     
     
         17 . A lithographic projection apparatus, comprising: 
 a radiation system configured to supply a beam of radiation;    a support configured to support a patterning device, the patterning device configured to pattern the beam according to a desired pattern;    a substrate table configured to hold a substrate;    a projection system configured to project the patterned beam onto a target portion of the substrate; and    a substrate for EUV lithography being at least partially covered by a photoresist layer, and an EUV transmissive top coat on the photoresist layer, wherein the EUV transmissive top coat comprises a polymer that includes one or more of the following atoms: beryllium, boron, carbon, silicon, zirconium, niobium and molybdenum.    
     
     
         18 . A method according to  claim 1 , wherein the top coat comprises silicon or boron.  
     
     
         19 . A method according to  claim 1 , wherein the top coat has a thickness of 20-100 nm.  
     
     
         20 . A method according to  claim 1 , wherein the top coat has a thickness of 30-80 nm.  
     
     
         21 . A method according to  claim 1 , wherein the EUV transmissive top coat on the photoresist layer is provided by spin coating or chemical vapor deposition.  
     
     
         22 . A method according to  claim 5 , wherein the top coat comprises silicon or boron.  
     
     
         23 . A method according to  claim 5 , wherein the top coat has a thickness of 20-100 nm.  
     
     
         24 . A method according to  claim 5 , wherein the top coat has a thickness of 30-80 nm.  
     
     
         25 . A method according to  claim 5 , wherein the EUV transmissive top coat on the photoresist layer is provided by spin coating or chemical vapor deposition.